def a(): print("I am from function a") person = { 'name' : 'john', 'age' : (10,12,), 'id' : [1,2,3,4], 'people' : {'name' : 'peter'}, 'func' : a } print(person) person['name'] = 'ann' # person['id'].append('ann') print(person) print(id(person['id'])) print(person['id'][1]) person['address'] = 'price building' print(person) del person['address'] print(person) person['people']['name'] = 'ann' print(person) person['func']() y = person['func']() print(y) # print "I am...a" firstly, and then print "None"